Hydrochloric Acid → 3-Chloro-2-methoxybenzoic acid

HRID 2417766Notes

Reaction equation

HRID 2417766 reaction equation
N([O-])=O.[Na+].N[C:6]1[C:7]([O:16][CH3:17])=[C:8]([CH:13]=[CH:14][CH:15]=1)[C:9]([O:11]C)=[O:10].[ClH:18]>O.CO.[OH-].[Na+]>[Cl:18][C:6]1[C:7]([O:16][CH3:17])=[C:8]([CH:13]=[CH:14][CH:15]=1)[C:9]([OH:11])=[O:10]

Participants

7

Reactant 3

HCID 313Hydrochloric Acid2×HCID 13338715Methyl 3-amino-2-methoxybenzoateHCID 23668193Sodium Nitrite

Product 1

HCID 64230443-Chloro-2-methoxybenzoic acidYield 24%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 14798Sodium HydroxideSolvent

Procedure

A solution of 1.2 g of sodium nitrite in 3 mL of water was added dropwise to a solution of 2 g (0.011 mole) of methyl 3-amino-2-methoxybenzoate in 15 mL of conc. HCl kept below 10° C. After completing the addition, stirring was continued for 0.5 hour at 0° C. The cold solution was then added dropwise to a solution of 2.5 g of cuprous chloride in 6 mL of concentrated HCl at 80°-85° C. After stirring at this temperature for 0.5 hour, the solution was chilled to precipitate an oil which was taken up in methylene chloride. After drying and removing the solvent, the oil obtained above was dissolved in 75 mL of methanol containing 7 mL of 10% NaOH. The solution was heated under reflux for 0.5 hour. After evaporation, the oil was treated with 40 mL of dilute HCl. A white solid precipitated to give 0.5 g (24%) of 3-chloro-2-methoxybenzoic acid after crystallization from ethyl acetate-hexane.

Workup

  1. customkept below 10° C
  2. additionthe addition
  3. stirringAfter stirring at this temperature for 0.5 hour
  4. temperaturethe solution was chilled
  5. customto precipitate an oil which
  6. customAfter drying
  7. customremoving the solvent
  8. customthe oil obtained
  9. temperatureThe solution was heated
  10. temperatureunder reflux for 0.5 hour
  11. customAfter evaporation
  12. additionthe oil was treated with 40 mL of dilute HCl
  13. customA white solid precipitated

Sources & evidence

ORD record
ord-26c27780e9e64583a5f823fec5d4c225
Source dataset
uspto-grants-1984_09
Patent number
US04470977

Reaction notes

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